It has been proposed to use fuel cells to supply power to small electronic devices, such as laptop computers, and for a variety of military uses, and it has also been proposed to provide hydrogen energy to those fuel cells from small cartridges containing metal hydrides that, at room temperature and/or higher temperature, generate a constant hydrogen partial pressure of suitable magnitude, as described in U.S. Pat. No. 6,447,945. However, to render such systems convenient and economical, it is necessary for the consumer, as well as the military, to be able to readily recharge such hydride storage cartridges as the cost of such cartridges is such that it is unlikely they would ever be a disposable item.
Although water electrolyzers have long been employed to create gaseous hydrogen and/or oxygen for commercial purposes, these devices have generally been designed for large scale operation, i.e. to produce relatively large quantities of H2 and/or O2 gas on an economical scale. Some efforts have been made to propose conceptual apparatus which might be suited for the present purpose; however, it is not believed that such has resulted in a truly commercially acceptable, small scale, hydrogen generator. Apparatus of this general type are shown in U.S. Pat. Nos. 5,037,518, 6,303,009, and 5,110,436; however, none of these has been considered to provide an adequate arrangement to efficiently generate hydrogen for small scale operations, such as refilling small cartridges designed to power portable electronic devices. Moreover, none has the ability to conveniently and efficiently handle and recharge cartridges that utilize high temperature metal alloy hydrides.
Accordingly, the search has continued for an apparatus that can be constructed to efficiently and economically supply hydrogen for recharging for such small cartridges and particularly for methods and systems for efficiently recharging high temperature hydride alloys in cartridges that are suitable for use in fuel cell power applications.